DD2 enrollment
Enrollment in DD2 includes a questionnaire and the collection of urine and blood samples. The questionnaire includes a section with a few questions for the patient to fill out (at registration for enrollment) and another to be filled out by the enroller (at enrollment). All individuals older than 18 years of age diagnosed with diabetes within the last 2 years are eligible for inclusion in DD2 (previously, a longer diabetes duration was allowed).
Individuals may either sign up online and be contacted later, or be approached by practice personnel during routine care. The individual will receive an e-mail with a link to WebPatient, where a few questions should be filled out before the questionnaire will be sent to the practice. Hereafter, a DD2 examination will take place, where additional questions will be answered (e.g., a clinically assessed date of diabetes onset) along with a physical examination (e.g., to measure weight, hip and waist circumference, and resting heart rate). The examination also involves a urine sample (morning urine) and a blood sample (fasting).
Enrollment can either take place in the general practice (GP) or in the outpatient clinic. Registration is also possible for individuals without internet access. For further information about the enrollment, please see the DD2 website (Danish): Patient information and Instructions and questionnaires.
The first individual was enrolled in DD2 in November 2010. Between 2010 and April 2023, the DD2 cohort enrolled 11,381 individuals. An additional 717 individuals were enrolled by November 2023, yielding a total of N=12,098 individuals. In the 2024 cohort paper (Kristensen et al. (2024)), we illustrated the enrollment during the period from November 2010 to April 2023.
Overview of enrollment in the DD2 cohort from November 2010 to April 2023. The plots show the cumulative and annual number of enrolled individuals.
The median age at enrollment was 61 years (IQR 53–69 years) and 41% were women (Kristensen et al. (2024)). Individuals are eligible for inclusion in DD2 if they are diagnosed with diabetes within the last 2 years (a longer diabetes duration was allowed in the early phase). Median diabetes duration at time of enrollment was 1.3 years (IQR 0.4–2.9 years) and 87% were already prescribed with glucose-lowering treatment at the time of enrollment (Kristensen et al. (2024)).
For more information about the enrollment and data collection, please contact DD2. Some of the general DD2 documents can also be downloaded here (Danish, downloaded 12 January 2024):